Winding coil assembly of reciprocating motor and manufacturing method thereof

ABSTRACT

A winding coil assembly ( 6 ) of a reciprocating motor comprising: an outer stator; an inner stator ( 2 ) arranged at an inner circumference surface of the outer stator ( 2 ) with a certain air gap; a magnet linearly and movably arranged between the outer stator and the inner stator; and a winding coil ( 20 ) mounted on either the outer stator or the inner stator, wherein the winding coil ( 20 ) is formed as a ring shape by being wound a coil ( 20 ) with a plurality of turns, and the coil ( 20 ) is molded by a molding material ( 22 ). According to this, the coil ( 20 ) is prevented from being deformed at the time of winding operation and can be manufactured to have a minute dimension, so that the number of components can be reduced and thereby a manufacture cost can be reduced.

TECHNICAL FIELD

The present invention relates to a reciprocating motor, and moreparticularly, to a winding coil assembly of a reciprocating motor whichcan simplify manufacturing processes and prevent a deformation of awinding coil, and a manufacturing method thereof.

BACKGROUND ART

FIG. 1 is a sectional view of a general reciprocating compressor.

The reciprocating compressor comprises: a hermetic case 106 where asuction pipe 102 and a discharge pipe 104 are connected to each other; areciprocating motor 108 arranged in the case 106 for generating areciprocating motion power; and a compressing unit 110 for compressing afluid by receiving the reciprocating motion power generated from thereciprocating motor 108.

The reciprocating motor 108 includes: an outer stator 112 having acylindrical shape accordingly as a plurality of thin lamination sheetsare radially stacked; an inner stator 114 arranged at an innercircumference surface of the outer stator 112 with a certain gap andhaving a cylindrical shape accordingly as a plurality of thin laminationsheets are radially stacked; magnets 116 arranged in a circumferencedirection between the outer stator 112 and the inner stator 114; and amagnet frame 120 to which the plurality of magnets 116 are fixed and themagnet frame 120 connected to a piston 118 which is to be reciprocated.

A winding coil assembly 124 for forming a flux between the outer stator112 and the inner stator 114 when a power is applied is mounted to theouter stator 112.

As shown in FIG. 2, the winding coil assembly 124 includes: a bobbin 130having a cavity 132 at an outer circumference surface thereof; a coil134 wound on the cavity 132 of the bobbin 130 by a plurality of turnsand fixed to the bobbin 130; and a cover 136 mounted at an outercircumference surface of the bobbin 130 on which the coil 134 is wound,and for covering the coil 134.

Herein, the bobbin 130 is manufactured by an injection molding with aplastic material, and the cover 136 is also formed with the same plasticresin as the bobbin 130.

Manufacturing processes of the winding coil assembly 124 will beexplained as follows. As shown in FIG. 3, the bobbin 130 is manufacturedby an injection molding as a ring shape having the cavity 132 at theouter circumference surface thereof. Next, the coated coil 134 is woundon the cavity 132 of the bobbin 130 by a plurality of turns, and thenthe cover 136 is mounted on the outer circumference surface of thebobbin 130. Subsequently, the winding coil is put in a die 138 andmanufactured by a die casting method.

However, in the winding coil assembly of a reciprocating motor inaccordance with the conventional art, since the bobbin 130 is formedwith a plastic material, an intensity of the bobbin 130 is weak thus tohave a problem that a deformation may occur when the coil 134 is woundon the cavity 132 of the bobbin 130. Besides, a winding intensity of thecoil 134 has to be properly controlled, thereby having difficultassembly processes.

Also, in order to wind the coil 134, the bobbin 130 and the cover 136are required, so that the number of components is increased and therebya manufacturing cost is increased.

Besides, the coil 134 is wound on the bobbin 130 and then the cover 136is mounted thereon and manufactured by the die 138 casting, so thatmanufacturing processes are complicated, the number of processes isincreased, and thereby a manufacturing cost is increased whereas aproductivity is lowered.

DISCLOSURE OF THE INVENTION

Therefore, it is an object of the present invention to provide a windingcoil assembly of a reciprocating motor which can prevent a coil frombeing deformed at the time of winding, minutely manufacture a coildimension, and increase a winding intensity.

Another object of the present invention is to provide a winding coilassembly of a reciprocating motor which can reduce the number ofcomponents and thus reduce a manufacturing cost.

Still another object of the present invention is to provide a windingcoil assembly of a reciprocating motor which can simplify manufacturingprocesses of a winding coil and thus enhance a productivity.

To achieve these objects, there is provided a winding coil assembly of areciprocating motor comprising: an outer stator; an inner statorarranged at an inner circumference surface of the outer stator with acertain air gap; a magnet linearly and movably arranged between theouter stator and the inner stator; and a winding coil mounted on eitherthe outer stator or the inner stator, wherein the winding coil is formedas a ring shape by being wound a coil with a plurality of turns, and thecoil is molded by a molding material.

The coil is manufactured by coating polyester imide layer on a surfaceof cooper wire, coating polyamide imide layer on the surface of thepolyester imide layer, and coating self-lubricating polyamide layer onthe surface of the polyamide imide layer.

A manufacturing method of the reciprocating motor according to thepresent invention comprises the steps of: winding a coil on a jig;firstly molding the wound coil; separating the firstly molded windingcoil from the jig; and secondly molding the winding coil separated fromthe jig.

The first molding is performed by heating the coil wound on the jig,thus melting the self-lubricating polyamide layer stacked at theoutermost side of the coil, and thereby bonding gaps between the coils.

The second molding is performed by inserting the winding coil into acavity of a die and then injecting molten metal into the cavity.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a general reciprocating compressor;

FIG. 2 is a perspective view of a winding coil assembly of areciprocating motor in accordance with the conventional art;

FIG. 3 is a view showing processes for manufacturing a winding coil of areciprocating motor in accordance with the conventional art;

FIG. 4 is a sectional view of a reciprocating motor according to oneembodiment of the present invention;

FIG. 5 is a perspective view of a winding coil assembly of areciprocating motor according to one embodiment of the presentinvention;

FIG. 6 is a sectional view of a winding coil according to one embodimentof the present invention; and

FIG. 7A to 7D are views showing processes for manufacturing a windingcoil assembly of a reciprocating motor according to one embodiment ofthe present invention.

MODES FOR CARRYING OUT THE PREFERRED EMBODIMENTS

Hereinafter, one embodiment of a reciprocating motor according to thepresent invention will be explained with reference to the attacheddrawings.

Even if several embodiments of the reciprocating motor according to thepresent invention can exist, the most preferred embodiment will beexplained.

FIG. 4 is a sectional view of a reciprocating motor according to oneembodiment of the present invention.

The reciprocating motor according to the present invention comprises: anouter stator 2 having a cylindrical shape accordingly as a plurality oflamination sheets are radially stacked; an inner stator 4 arranged at aninner circumference surface of the outer stator 2 with a certain gapthus to form a flux between the outer stator 2 and having a cylindricalshape accordingly as a plurality of lamination sheets are radiallystacked; a winding coil assembly 6 mounted on either the outer stator 2or the inner stator 4; a magnet 8 linearly and movably arranged betweenthe outer stator 2 and the inner stator 4; and a magnet frame 10connected between the magnet 8 and a piston 12 which is to bereciprocated thus for transmitting a reciprocating motion of the magnet8 to the piston 12.

Herein, in case that the reciprocating motor is applied to areciprocating compressor, the piston 12 linearly reciprocates in thecylinder 14 for compressing.

The winding coil assembly according to the present invention is mountedto the outer stator 2.

As shown in FIG. 5, the winding coil assembly 6 is formed as a circularshape having a certain thickness and a width accordingly as the coil 20is wound by a plurality of turns, and a molding material 22 forinsulating gaps between the coils 20 and maintaining a shape of a woundcoil is placed between the coils 20.

The coil 20 before winding, as shown in FIG. 6, is constituted with acopper wire 30, a polyester imide layer 32 stacked on the surface of thecopper wire 30, a polyamide imide layer 34 stacked on the surface of thepolyester imide layer 32, and a self-lubricating polyamide layer 36stacked on the surface of the polyamide imide layer 34.

As another embodiment of the coil, it is possible that the polyesterimide layer 32 and the self-lubricating polyamide layer 36 aresequentially stacked on the surface of the copper wire 30, or thepolyamide imide layer 34 and the self-lubricating polyamide layer 36 aresequentially stacked on the surface of the copper wire 30.

The polyester imide layer 32 improves an insulating characteristic withthe copper wire 30 since the lamination sheets are directly stacked onthe outer circumference surface of the wound coil 20. Also, thepolyamide imide layer 34 enhances a physical strength of the wound coil20 in order to additional bobbins and etc. are not required. Besides,the self-lubricating polyamide layer 36 makes the reciprocating motorresist against a compression condition of high temperature and highpressure when the reciprocating motor is applied to the compressor.

Manufacture processes of the winding coil assembly will be explained asfollows.

FIGS. 7A to 7D are views showing manufacture processes of a winding coilassembly according to one embodiment of the present invention.

First, as shown in FIG. 7A, a jig 40 having a cavity 42 where the coil20 is wound in a circumference direction is prepared, and then the coil20 is wound on the cavity 42 of the jig 40 by the desired number ofturns. Herein, the jig 40 has an intensity of a certain degree, so thata winding intensity of the coil 20 can be freely controlled and thenumber of winding and a shape of the coil 20 can be freely set.

Under this state, as shown in FIG. 7B, a first molding layer 44 formedsurface of the coil 20 for bonding between the coils 20 by heating thecoil 20 wound on the jig 40 by applying an electric current or othermethod. That is, when the wound coil 20 is heated, the self-lubricatingpolyamide layer 36 is coated on the outermost side of the coil 20 ismelted thus to form the first molding layer 44 for bonding between thecoils 20.

When the first molding is completed, as shown in FIG. 7C, the windingcoil 20 where the first molding layer 44 is formed is separated from thejig 40. Then, as shown in FIG. 7D, the winding coil 20 separated fromthe jig 40 is inserted into a die 50 having a round cavity 48 and thenmolten metal of an insulation material is injected thereto, thus asecond molding of the winding coil 20 is performed and thereby thewinding coil assembly is manufactured.

The winding coil assembly of a reciprocating motor can freely control awinding intensity of the coil wound on the jig by firmly manufacturingthe jig thus to facilitate a winding operation of the coil, to preventthe coil from being deformed at the time of winding, and to maintain adimension of the winding coil accurately.

Also, additional components, that is, bobbins and covers are notrequired at the time of manufacturing the winding coil, so that amanufacture cost can be reduced, manufacture processes can be reduced,and thereby a productivity can be increased.

Besides, by sequentially applying the polyester imide layer, thepolyamide imide layer, and the self-lubricating polyamide layer on thesurface of the copper wire, an insulation characteristic and a physicalintensity can be reinforced and the reciprocating motor can effectivelyresist against a condition of high temperature and high pressure such asa compressor. According to this, the reciprocating motor can have aprolonged life span and an increased productivity.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the invention. Thus, it isintended that the present invention cover modifications and variationsof this invention provided they come within the scope of the appendedclaims and their equivalents.

1. A winding coil assembly of a reciprocating motor comprising: an outerstator; an inner stator arranged at an inner circumference surface ofthe outer stator with a certain air gap; a magnet linearly and movablyarranged between the outer stator and the inner stator; and a windingcoil mounted on either the outer stator or the inner stator, wherein thewinding coil is formed as a ring shape by being wound a coil with aplurality of turns, and the coil is integrally molded by a moldingmaterial of coil.
 2. The winding coil assembly of claim 1, wherein thecoil is manufactured by sequentially coating polyester imide layer andself-lubricating polyamide layer on a surface of copper wire. Thewinding coil assembly of claim 1, wherein the coil is manufactured bycoating polyester imide layer on a surface of cooper wire, coatingpolyamide imide layer on a surface of the polyester imide layer, andcoating self-lubricating polyamide layer on a surface of the polyamideimide layer.
 3. The winding coil assembly of claim 1, wherein the coilis manufactured by coating polyester imide layer on a surface of cooperwire, coating polyamide imide layer on a surface of the polyester imidelayer, and coating self-lubricating polyamide layer on a surface of thepolyamide imide layer.
 4. The winding coil assembly of claim 1, whereinthe coil is manufactured by sequentially coating polyamide imide layerand self-lubricating polyamide layer on a surface of copper wire.
 5. Awinding coil assembly of a reciprocating motor comprising: an outerstator; an inner stator arranged at an inner circumference surface ofthe outer stator with a certain air gap; a magnet linearly and movablyarranged between the outer stator and the inner stator; and a windingcoil mounted on either the outer stator or the inner stator, wherein thewinding coil is formed as a ring shape by being wound a coil with aplurality of turns, and the coil is firstly molded by a molding materialand secondly molded by a die.
 6. The winding coil assembly of claim 5,wherein the coil is manufactured by coating polyester imide layer on asurface of cppoer wire, coating polyamide imide layer on a surface ofthe polyester imide layer, and coating self-lubricating polyamide layeron a surface of the polyamide imide layer.
 7. A manufacturing method ofa winding coil of a reciprocating compressor comprising the steps of:winding a coil on a jig; firstly molding the wound coil; separating thefirstly molded winding coil from the jig; and secondly molding thewinding coil separated from the jig.
 8. The method of claim 7, whereinthe jig has a cavity where a coil is wound in a circumference directionand has a certain intensity which can freely control of a windingintensity of the coil.
 9. The method of claim 7, wherein the firstmolding s performed by heating the coil wound on the jig, thus meltingthe self-lubricating polyamide layer stacked at the outermost side ofthe coil, and thereby bonding gaps between the coils.
 10. The method ofclaim 7, wherein the second molding is performed by inserting thewinding coil into a cavity of a die and then injecting molten metal intothe cavity.